Reception of Downlink Data for Coordinated Multi-Point Transmission in the Event of Fall-Back

ABSTRACT

Systems and methods for fall-back rate-matching and timing for user equipment (UE) configured for downlink (DL) Coordinated Multi-Point Transmission (CoMP) are disclosed. In one embodiment, when a UE configured in DL CoMP receives a fall-back transmission, PDSCH is rate-matched around the serving cell CRS. In an alternative embodiment, when a UE configured in DL CoMP receives a fall-back transmission, PDSCH is rate-matched or uses timing around one of the cell-specific reference symbol (CRS) resource element (RE) set indicated by RRC-higher layer signaling. For example, PDSCH may be rate-matched or use timing around the first RRC higher layer configured CRS RE set.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the filing date of U.S.provisional patent application No. 61/693,854, filed Aug. 28, 2012, thedisclosure of which is hereby incorporated herein by reference in itsentirety.

BACKGROUND

A LTE wireless network consists of multiple base stations. Each basestation, such as an Evolved Node B (eNodeB or eNB), may be configured asa single cell with its own cell ID and assigned to cover a specificserving area. In a conventional wireless network, mobile terminals orUser Equipment (UE) are always connected to and receive uplink (UL) anddownlink (DL) data from one connected cell, with single-celltransmission/reception. In the downlink, transmissions from other basestations generate inter-cell interference to the UB. In the uplink, theUE's transmissions to its serving cell generate inter-cell interferenceto other cells or base stations.

SUMMARY OF THE INVENTION

For DL Coordinated Multi-Point Transmission (CoMP), the transmissionpoint (e.g., cell) transmitting downlink data may switch dynamically ona per-subframe basis. Because different cells may have differentCell-Specific Reference Symbols (CRS) (e.g., different antenna portnumbers, frequency shifts), it is necessary to signal the CRS patternaround which the UE may assume Physical Downlink Shared Channel (PDSCH)rate matching. An n-bit information field can be included in theDownlink Control Information (DCI) format for DL CoMP scheduling. Eachcodepoint corresponds to a Radio Resource Control (RRC) higher layerconfigured CRS Resource Element (RE) set, around which PDSCH israte-matched.

Fall-back operation is needed for all cellular systems in which an eNBuses a compact DCI format (e.g., DCI 1A) to perform data scheduling.When a CoMP UE receives fall-back scheduling on DCI 1A, the UE needs toknow the CRS REs for PDSCH rate-matching.

In one embodiment, when a UE configured in DL CoMP receives a fall-backtransmission, PDSCH is rate-matched around the serving cell CRS.

In an alternative embodiment, when a UE configured in DL CoMP receives afall-back transmission, PDSCH is rate-matched around one of the CRS REsindicated by RRC-higher layer signaling. For example, PDSCH may berate-matched around the first RRC higher layer configured CRS RE set.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, wherein:

FIG. 1 is a block diagram illustrating a wireless network according toone embodiment.

FIGS. 2A-C are diagrams of single-cell CRS patterns used in variousembodiments.

FIG. 3 is a high level block diagram of a system that may be used as aneNB or UE in various embodiments.

FIG. 4 is a flowchart illustrating a method for determining PDSCHrate-matching according to one embodiment.

FIG. 5 is a flowchart illustrating a method for determining PDSCH timingaccording to another embodiment.

DETAILED DESCRIPTION

The invention now will be described more fully hereinafter withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Oneskilled in the art may be able to use the various embodiments of theinvention.

Coordinated Multi-Point Transmission (CoMP) is used to send and receivedata to and from a UE and multiple transmission points. The transmissionpoints may include, for example, an eNodeB configured as a cell, macrocell, pico cell, femto cell, remote radio head, distributed antennas,other wireless transmission entity, or a combination thereof. Thetransmission points coordinate with each other to jointly optimize thedownlink beamforming signals, including the beamforming vectors,transmission power, and/or scheduling decisions. Unlike traditionalwireless networks in which signals from other transmission points createco-channel interference, coordination between multiple transmissionpoints allow the signals to be cooperatively designed to reduceco-channel interference, boost received signal-to-noise ratio (SNR),increase cell-average throughput, and improve cell-edge coverage.

The following types of CoMP transmission schemes are possible.

Joint Transmission (JT) allows simultaneous data transmission frommultiple points to a single UE or multiple UEs in a time-frequencyresource. Data to a UE is simultaneously transmitted from multiplepoints. The data may be coherently or non-coherently transmitted improvethe received signal quality and/or data throughput and/or cancelactively interference for other UEs.

Dynamic Point Selection (DPS) allows data transmission from one point ateach time instance. The actual transmitting point may change from onesubframe to another. Data is available simultaneously at multiplepoints.

Mapping of Downlink Data in Presence of Reference Signals.

FIG. 1 is a block diagram illustrating a wireless network 100, which maybe an LTE network that utilizes Orthogonal Frequency-Division MultipleAccess (OFDMA) on the downlink and Single-Carrier Frequency DivisionMultiple Access (SC-FDMA) on the uplink. LTE partitions system bandwidthinto multiple orthogonal subcarriers, which may be referred to asfrequency tones or frequency bins. Each subcarrier may be modulated withdata, control, or reference signals. The wireless network 100 includes anumber of eNBs 101-104 and other network entities. The eNBs 101-104communicate with a UE 105. Each eNB 101-104 provides communicationservices for a particular geographic area or “cell”.

UE 105 may be stationary or mobile and may be located throughout thewireless network 100. UE 105 may be referred to as a terminal, a mobilestation, a subscriber unit, a station, such as a mobile telephone, apersonal digital assistant (PDA), a wireless modem, a laptop or notebookcomputer, a tablet, and the like. A UE 105 may communicate with morethan one eNB 101-104. One eNB 101 will be the primary cell (PCell) andthe other eNBs 102-104 will be secondary serving cells (SCell).

Reference signals are essential for the operation of wireless network100. A wireless network necessarily has different types of referencesignals, which are usually transmitted with data simultaneously frombase stations 101-104. For example, the LTE downlink system includesprimary synchronization signals (PSS) and secondary reference signals(SSS), cell-specific reference signals (CRS), channel state informationreference signal (CSI-RS), and demodulation reference signals (DMRS).

PSS/SSS are cell-specific and enable a UE 105 to perform cell search andinitial synchronization. When UE 105 powers up, it blindly detects thePSS/SSS of several cells 101-104, and connects to the strongest cell 101with the highest signal strength. The connected cell 101 is identifiedby UE 105 as the “serving cell” and provides all essential systeminformation to maintain connection to the wireless network 100. The cellID of the serving cell 101 is derived by UE 105 as a function of thePSS/SSS. The PSS/SSS also provides the initial timing synchronization sothat UE 105 understands the time domain starting position of eachsubframe.

CRS are cell-specific, non-precoded, and allows UE 105 to continuouslytrack the downlink timing. In an LTE system, {1, 2, 4} CRS antenna portscan be configured by a base station, and the time/frequency resourceelements (RE) occupied by CRS antenna ports are determined by the numberof CRS antenna ports. Resource element is the minimum time-frequencyunit in LTE which corresponds to one OFDM subcarrier in one OFDM symbol.In the time domain, each subframe is of 1 ms duration and comprises 14OFDM symbols. In the frequency domain, one subframe comprises N resourceblocks where each resource block consists of 12 OFDM subcarriers. N is afunction of the system bandwidth, e.g., N 6/15/25/50/100 for1.4/3/5/10/20 MHz system bandwidth. The CRS of each cell 101-104 is alsoshifted in the frequency domain in order to achieve inter-cellrandomization, where the frequency shift is a function of the cell ID.Note that an eNodeB 101-104 may configure up to 6 Multicast-BroadcastSingle Frequency Network (MBSFN) subframes out of every 10 subframes,where no CRS are transmitted in the MBSFN sub frames.

CSI-RS are a set of non-precoded signals on which UE 105 performschannel state information measurement and feedback. In LTE, the UE 105does not directly feed-back the wireless channel, but feeds back a setof recommended Multiple-Input/Multiple-Output (MIMO) transmissionproperties including rank indicator, precoding matrix indicator, channelquality indicator. Rank indicator (RI) is the number of data streamsthat UE 105 can reliably receive. A precoding matrix indicator (PMI)corresponds to a precoding vector that the UE 105 recommends fordownlink precoding. A channel quality indicator (CQI) reflects thechannel quality/strength, and is often quantized as the signal-to-noiseratio (SNR), or size of the transport block recommended for downlinktransmission.

DMRS are UE-specific, precoded by the same precoder as data, andtransmitted only in the frequency blocks in which UE 105 receives datatransmission. DMRS enables UE 105 to directly measure precoding channelwithout knowing the precoding vector.

In legacy LTE single-cell transmission (e.g., LTE Rel. 8-10), downlinkdata transmission is initiated from a single serving cell 101. Tocorrectly receive data transmission, UE 105 only needs to take intoaccount the RS pattern of the serving cell. More specifically, PDSCHdata is rate-matched around the CRS and is not mapped to any resourceelements occupied by the CRS of the serving cell 101.

FIGS. 2A-C are diagrams of single-cell CRS patterns. FIG. 2A is for 1port CRS. FIG. 2B is for 2 port CRS. FIG. 2C is for 4 port CRS.Different cells may be configured with different numbers of CRS antennaports. In addition, the CRS of a cell may be shifted byCRS_(shift)=mod(PCI, 6) subcarriers in the frequency domain, where PCIis the Physical Cell ID.

For CoMP operation, the LTE network 100 configures multiple (N) CSI-RSresources, where each CSI-RS resource corresponds to a transmissionpoint 101-104. UE 105 measures the per-point channel of eachtransmission point 101-104 using the corresponding CSI-RS resource.However the UE 105 may not necessarily need to know the associationbetween each CSI-RS resource and a transmission point. The N CSI-RSrecourses are defined as the CoMP measurement set.

Mapping of Downlink Data in Presence of Reference Signals for CoMP.

For DL CoMP, the transmission points 101-104 transmitting downlink datamay switch dynamically on a per-subframe basis. Because different cells101-104 may have different CRS patterns (e.g., number of antenna ports,frequency shift), it is necessary to signal the CRS pattern around whicha UE 105 may assume PDSCH rate matching. For that, an n-bit informationfield can be included in downlink control signal or downlink controlindicator (DCI) format dedicated for DL CoMP scheduling. Each codepointof the n-bit information field corresponds to a RRC higher layerconfigured CRS RE set, around which PDSCH is rate-matched. For example,in one embodiment, the RRC higher layer may configure four possible CRSRE sets. Each CRS RE set comprises of a set of CRS resource elementsthat may be associated to one or a set of transmission points 101-104 inCoMP transmission.

A two-bit signaling field in the dynamic DCI format for CoMP schedulingmay be used to dynamically signal one of the four CRS RE sets for PDSCHrate-matching. Each CRS RE set may not correspond to a single-cell CRSpattern. If a CRS RE set corresponds to the combination of multiplesingle-cell CRS patterns, the CRS RE set can be used for jointtransmission from multiple cells. An example of the two-bit CRSsignaling field and associated UE assumption is given in Table 1.

TABLE 1 CRS RE signaling field in DCI format UE assumption on PDSCHrate-matching 00 PDSCH rate-matching around the 1^(st) set of CRS REsconfigured by higher layer 01 PDSCH rate-matching around the 2^(nd) setof CRS REs configured by higher layer 10 PDSCH rate-matching around the3^(rd) set of CRS REs configured by higher layer 11 PDSCH rate-matchingaround the 4^(th) set of CRS REs configured by higher layer

After the UE 105 successfully establishes connection to the network 100,the serving cell 101 configures the UE in a specific downlinktransmission mode. In every radio subframe the UE 105 monitors adedicated DCI format associated with the configured DL transmissionmode; if such a DCI format is found, the UE proceeds to decode PDSCHdownlink data according control information carried by the DCI. Inaddition, in every subframe UE 105 also needs to monitor a fall-back DCIformat 1A; if fall-back DCI format 1A is found by the UE 105, UE decodesdownlink PDSCH data using control information carried by DCI 1A.Fall-back operation is critical for all cellular systems. Duringfall-back, the base station 101 uses a compact DCI format (e.g., DCI 1A)to schedule downlink transmission to UE 105. Data transmission fallsback to a single-layer transmit diversity (TxD)-based transmission.Fall-back may be performed for the following reasons.

The DCI format used for fall-back scheduling has a smaller size andbetter coverage than the dedicated DCI format associated with theconfigured downlink transmission mode. When a large number of UEs needto be scheduled in one subframe, the control channel capacity may belimited. In this case, the network may use the fall-back transmission toalleviate the control channel constraint.

The network may need to switch a UB from its present transmission modeto a different transmission mode through Radio Resource Control (RRC).During the switching period, fallback is used to maintain the UE'sconnection to the wireless network until mode switching is successfullyfinished by RRC reconfiguration.

The wireless channel condition may experience fluctuations, particularlywhen a UE moves quickly or is surrounded by high-rise buildings thatcause large signal penetration loss. The channel quality deteriorationmay be large enough so that the network is unsure if the UE can reliablyreceive its normal data and control channel DCI format. In this case,the network will fall-back to the more robust single-layer TxD-basedtransmission scheme to ensure that downlink connection to the UE is notlost. Similarly, such that the DCI format of the configured transmissionmode may not be received reliably due to channel quality deterioration.Since fall-back uses a smaller-size DCI format and uses robustsingle-layer transmission scheme for downlink data, it ensures robustreception of the control channel.

When a CoMP UE receives a fall-back scheduling on DCI 1A, it needs toknow the CRS REs for PDSCH rate-matching. However, current fall-back DCIformat 1A assumes single-cell mapping. Accordingly, it carries noinformation regarding the CRS for PDSCH rate-matching. In oneembodiment, when a UE configured in DL CoMP receives a fall-backtransmission, PDSCH is rate-matched around the serving cell CRS. Thismay correspond to a scenario where downlink PDSCH data is transmitted bythe serving cell 101 or by another cell 102-104 whose CRS pattern is asubset of the CRS pattern of the serving cell 101. Alternatively, when aUE configured in DL CoMP receives a fall-back transmission, PDSCH israte-matched around one of the CRS RE set indicated by RRC higher layersignaling. For example, PDSCH may be rate-matched around the 1^(st) RRChigher layer configured CRS RE set, corresponding to the “00” field inTable 1. This is applicable to the scenario of semi-static pointselection, for example, where codepoint “00” field in Table 1 isconfigured by the network to correspond to a cell (e.g., 102) other thanthe serving cell 101.

Reception Timing for CoMP.

Reception timing is an important factor to be considered in CoMPoperation. In an OFDM system, the downlink timing of the PDSCH datatransmission needs to be known at UE 105 in order to perform correctFast Fourier Transform (FF) processing and removal of Cyclic Prefix(CP). UE obtains initial timing acquisition to the serving cell 101through the PSS/SSS, and tracks the downlink timing of serving cell 101by the CRS or CSI-RS of the serving cell 101. In single-celltransmission, the UE 105 usually muses the timing of its downlinkreference signals (CRS or CSI-RS) for PDSCH demodulation and does notperform a separate timing estimation on PDSCH. This reduces UE 105complexity and would work perfectly in single-cell transmission becausethe PDSCH data and reference signals (CRS or CSI-RS) are originated fromthe same base station.

For multi-point transmission, in a particular subframe the UE mayreceive downlink PDSCH data from a cell 102-104 other than its servingcell 101. Because the propagation delay from different transmissionpoints 101-104 may be different, UE can no longer reuse the downlinktiming of cell 101 when receiving PDSCH data from another cell 102-104.The exact timing for PDSCH reception needs to be signaled to UE 105. Inone embodiment, the higher layer may configure a set of timingassumptions, and dynamically indicates one timing assumption to the UE105. Such dynamic signaling could reuse that of the CRS patternsignaling. For example, the CRS RE signaling and the timing signalingmay be jointly encoded in the DCI format. Such a timing assumption couldbe either associated with the CRS or to one of the N configured CSI-RSresources in the CSI-RS measurement set. Table 2 illustrates an exampletable of PDSCH rate-matching and timing assumptions for a two-bit CRS REsignaling field in DCI format.

TABLE 2 CRS RE signaling in UE assumption on UE assumption on DCI formatPDSCH rate-matching PDSCH timing field 00 PDSCH rate-matching PDSCHtiming uses that of the around the 1^(st) set of 1^(st) CSI-RS resourceCRS REs configured by in CoMP measurement set higher layer 01 PDSCHrate-matching PDSCH timing uses that of the around the 2^(nd) set of2^(nd) CSI-RS resource CRS REs configured by in CoMP measurement sethigher layer 10 PDSCH rate-matching PDSCH timing uses that of the aroundthe 3^(rd) set of 3^(rd) CSI-RS resource CRS REs configured by in CoMPmeasurement set higher layer 11 PDSCH rate-matching PDSCH timing usesthat of the around the 4^(th) set of 4^(th) CSI-RS resource CRS REsconfigured by in CoMP measurement set higher layer

When a CoMP UE receives a fall-back scheduling on DCI 1A, the UB needsto know the timing for PDSCH demodulation. However, the current fallbackDCI format 1A carries no timing information. In one embodiment, when aUE configured in DL CoMP receives a fall-back transmission, PDSCH timinguses the timing of the serving cell CRS. Alternatively, when a UEconfigured in DL CoMP receives a fall-back transmission, PDSCH timinguses one of the timing assumptions indicated by RRC-higher layersignaling. For example, PDSCH timing follows that of the 1^(st) RRChigher layer configured timing assumption, corresponding to the “00”field in Table 2.

FIG. 3 is a high level block diagram of a system 300 that may be used asan eNB or UE, which may be, for example, eNBs 101-104 or UE 105 inFIG. 1. System 300 receives data to be transmitted from an interface 301at transmit processor 302. The data may include, for example, audio orvideo information or other data file information to be transmitted on aPUSCH. The transmit processor 302 may also receive control informationto be transmitted on a PUSCH from a controller 303. Transmit processor302 processes (e.g., encode and symbol map) the data and controlinformation to obtain data symbols, control symbols, and referencesymbols. The transmit processor 302 may also perform spatial processingor precoding on the data symbols and/or the control symbols andreference symbols. The output of the transmit processor 302 is providedto a modem 304. Modem 304 processes the output symbol stream from thetransmit processor 302 to obtain an output sample stream that is furtherprocessed by converting to analog, amplifying, and upconverting beforebeing transmitted via antenna 305. In other embodiments, multiple modems304 may be used to support (MIMO) transmission on multiple antennas 305.

Signals are also received at system 300 on antenna 305 from otherdevices. The received signals are provided to modem 304 fordemodulation. Modem 304 processes the signals by filtering, amplifying,downconverting, and/or digitizing, for example, to obtain input samples.For example, modem 304 may receive a fall-back transmission from a basestation when the device 300 is a UE configured for downlink CoMP. Modem304 or a receive processor 306 may further process the input samples toobtain received symbols. Receive processor 306 then processes thesymbols by demodulating, deinterleaving, and/or decoding. For example,in response to the fall-back transmission, receive processor 305 mayperform PDSCH demodulation assuming PDSCH rate-matching based upon adefault CRS RE set Receive processor 305 may further determine a valueof a CRS RE signaling field in a DCI signal received from a basestation. If no fall-back transmission is received, receive processor 305may perform PDSCH demodulation assuming rate-matching based upon a CRSRE set corresponding to the value in the downlink control signal,wherein the value of the CRS RE signaling field in the DCI signalcorresponds to a CRS RE set configured by a RRC higher layer. Otherwise,in response to the fall-back transmission, receive processor 305 mayperform PDSCH demodulation assuming rate-matching based upon a defaultCRS RE set. The default CRS RE set may be selected from a serving basestation CRS RE set, a first CRS RE set of a plurality of CRS RE setsconfigured by the RRC higher layer.

Receive processor 306 provides decoded data to interface 301 for use bythe eNB or UE. Receive processor further provides decoded controlinformation to controller 303. Controller 303 may direct the operationof system 300 in the eNB or UE, such as by adjusting timing and powerlevels. A memory 307 may store data and program codes for controller303, transmit processor 302, and/or receive processor 306. Additionalcomponents, such as a scheduler 308 may schedule downlink and/or uplinkdata transmission on one or more component carriers by system 300 (e.g.,in an eNB).

FIG. 4 is a flowchart illustrating a method for determining PDSCHrate-matching according to an example embodiment. In step 401, the UEdetermines a value of a CRS RE signaling field in a DCI signal receivedfrom a base station. In step 402, if no fall-back transmission isreceived, the UE performs PDSCH demodulation assuming rate-matchingbased upon a CRS RE set corresponding to the value in the downlinkcontrol signal.

In step 403, a fall-back transmission is received from a base station ata UE configured for downlink CoMP. In step 404, in response to thefall-back transmission, the UE performs PDSCH demodulation assumingPDSCH rate-matching based upon a default CRS RE set. The fall-backtransmission may be on a compact DCI format, such as fall-backscheduling on a DCI 1A format. The default CRS RE set may be a servingbase station CRS RE set or a first CRS RE set of a plurality of CRS REsets configured by a RRC higher layer. The value of the CRS RE signalingfield in the DCI signal may correspond to a CRS RE set configured by aRRC higher layer, for example.

FIG. 5 is a flowchart illustrating a method for determining PDSCH timingaccording to another example embodiment. In step 501, the UE determinesa value of a CRS RE signaling field in a DCI signal received from a basestation. In step 502, if no fall-back transmission is received, the UEperforms PDSCH demodulation using downlink timing for a CSI-RS resourcecorresponding to the value in the downlink control signal.

In step 503, a fall-back transmission is received from a base station ata UE configured for downlink CoMP. In step 504, in response to thefall-back transmission, the UE performs PDSCH demodulation using adefault PDSCH timing assumption. The default PDSCH timing may be timingfor a default CRS RE set or a CSI-RS resource. Alternatively, thedefault PDSCH timing may be timing of a serving base station CRS or afirst CSI-RS resource of a plurality of CSI-RS resources configured by aRRC higher layer. The fall-back transmission may be on a compact DCIformat, such as fall-back scheduling on a DCI 1A format.

Alternatively, in step 505, in response to the fall-back transmission,the UE performs PDSCH demodulation using downlink timing for a defaultCRS RE set or a first CSI-RS resource of a plurality of CSI-RS resourcesconfigured by a RRC higher layer. The default CRS RE set may be aserving cell CRS. The value of the CSI-RS resource signaling field inthe DCI signal may correspond to a CSI-RS resource configured by the RRChigher layer.

Many modifications and other embodiments of the invention will come tomind to one skilled in the art to which this invention pertains havingthe benefit of the teachings presented in the foregoing descriptions,and the associated drawings. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments disclosed.

Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1-20. (canceled)
 21. A method for operating a user equipment (UE)comprising: configuring the UE to operate in transmission mode 10;receiving a downlink control information (DCI) signal; and wherein afield of the DCI is used to determine the PDSCH parameter set.
 22. Amethod for operating a user equipment (UE) comprising: configuring theUE to operate in transmission mode 10; receiving a downlink controlinformation (DCI) signal; selecting the PDSCH parameter set indicated bya DCI field if the DCI format 2D is used; and selecting parameter set 1if the DCI format 1A is used.
 23. A method for operating a userequipment (UE) comprising: configuring the UE to operate in transmissionmode 10; receiving a downlink control information (DCI) signal; anddecoding the physical downlink shared channel (DPSCH) using a parameterset wherein the PDSCH parameter set is indicated by a DCI field if theDCI is of format 2D and the PDSCH parameter set 1 is used if the DCI isof format 1A.
 24. A method for operating a user equipment (UE)comprising: configuring the UE for reception of coordinated multipoint(CoMP) transmission; receiving a downlink control information (DCI)signal; and wherein a field of the DCI is used to determine the PDSCHparameter set.
 25. A method for operating a user equipment (UE)comprising: configuring the UE for reception of coordinated multipoint(CoMP) transmission; receiving a downlink control information (DCI)signal; selecting the PDSCH parameter set indicated by a DCI field ifthe DCI format 2D is used; and selecting parameter set 1 if the DCIformat 1A is used.
 26. A method for operating a user equipment (UE)comprising: configuring the UE for reception of coordinated multipoint(CoMP) transmission; receiving a downlink control information (DCI)signal; and decoding the physical downlink shared channel (DPSCH) usinga parameter set wherein the PDSCH parameter set is indicated by a DCIfield if the DCI is of format 2D and the PDSCH parameter set 1 is usedif the DCI is of format 1A.
 27. The method of claim 21, wherein theparameter sets are configured by higher layer signaling.
 28. The methodof claim 22, wherein the parameter sets are configured by higher layersignaling.
 29. The method of claim 23, wherein the parameter sets areconfigured by higher layer signaling.
 30. The method of claim 24,wherein the parameter sets are configured by higher layer signaling. 31.The method of claim 25, wherein the parameter sets are configured byhigher layer signaling.
 32. The method of claim 26, wherein theparameter sets are configured by higher layer signaling.
 33. A userequipment (UE) apparatus comprising: circuitry for configuring the UE tooperate in transmission mode 10; circuitry for receiving a downlinkcontrol information (DCI) signal; and wherein a field of the DCI is usedto determine the PDSCH parameter set.
 34. A user equipment (UE)apparatus comprising: circuitry for configuring the UE to operate intransmission mode 10; circuitry for receiving a downlink controlinformation (DCI) signal; circuitry for selecting the PDSCH parameterset indicated by a DCI field if the DCI format 2D is used; and circuitryfor selecting parameter set 1 if the DCI format 1A is used.
 35. A userequipment (UE) apparatus comprising: circuitry for configuring the UE tooperate in transmission mode 10; circuitry for receiving a downlinkcontrol information (DCI) signal; circuitry for decoding the physicaldownlink shared channel (DPSCH) using a parameter set wherein the PDSCHparameter set is indicated by a DCI field if the DCI is of format 2D andthe PDSCH parameter set 1 is used if the DCI is of format 1A.
 36. A userequipment (UE) apparatus comprising: circuitry for configuring the UEfor reception of coordinated multipoint (CoMP) transmission; circuitryfor receiving a downlink control information (DCI) signal; and wherein afield of the DCI is used to determine the PDSCH parameter set.
 37. Auser equipment (UE) apparatus comprising: circuitry for configuring theUE for reception of coordinated multipoint (CoMP) transmission;circuitry for receiving a downlink control information (DCI) signal;circuitry for selecting the PDSCH parameter set indicated by a DCI fieldif the DCI format 2D is used; and circuitry for selecting parameter set1 if the DCI format 1A is used.
 38. A user equipment (UE) apparatuscomprising: circuitry for configuring the UE for reception ofcoordinated multipoint (CoMP) transmission; circuitry for receiving adownlink control information (DCI) signal; and circuitry for decodingthe physical downlink shared channel (DPSCH) using a parameter setwherein the PDSCH parameter set is indicated by a DCI field if the DCIis of format 2D and the PDSCH parameter set 1 is used if the DCI is offormat 1A.
 39. The apparatus of claim 33, wherein the parameter sets areconfigured by higher layer signaling.
 40. The apparatus of claim 34,wherein the parameter sets are configured by higher layer signaling. 41.The apparatus of claim 35, wherein the parameter sets are configured byhigher layer signaling.
 42. The apparatus of claim 36, wherein theparameter sets are configured by higher layer signaling.
 43. Theapparatus of claim 37, wherein the parameter sets are configured byhigher layer signaling.
 44. The apparatus of claim 38, wherein theparameter sets are configured by higher layer signaling.